package A1_二叉树;

public class LC_226翻转二叉树_前序 {
    public static class TreeNode{
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode(){}
        TreeNode(int val){
            this.val=val;
        }
        TreeNode(int val,TreeNode left,TreeNode right){
            this.val=val;
            this.left=left;
            this.right=right;
        }
    }

    public static TreeNode invertTree(TreeNode root) {
        if(root==null)
            return root;
        TreeNode node=root.left;
        root.left=root.right;
        root.right=node;
        invertTree(root.left);
        invertTree(root.right);
        return root;

    }
}
